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ICNRG                                                      S. Mastorakis
Internet-Draft                                                      UCLA
Intended status: Experimental                                  J. Gibson
Expires: March 23, 2017                                     I. Moiseenko
                                                                R. Droms
                                                                 D. Oran
                                                           Cisco Systems
                                                      September 19, 2016


                 ICN Traceroute Protocol Specification
                draft-mastorakis-icnrg-icntraceroute-00

Abstract

   This document presents the design of an ICN Traceroute protocol.
   This includes the operations both on the client and the forwarder
   side.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on March 23, 2017.

Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
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   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   2
   2.  Background on IP-Based Traceroute Operation . . . . . . . . .   3
   3.  Traceroute Functionality Challenges and Opportunities in ICN    3
   4.  ICN Traceroute Packet Formats . . . . . . . . . . . . . . . .   5
     4.1.  ICN Traceroute Request Packet Format  . . . . . . . . . .   6
     4.2.  Traceroute Reply Packet Format  . . . . . . . . . . . . .   8
   5.  Forwarder Handling  . . . . . . . . . . . . . . . . . . . . .  11
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  13
   Appendix A.  Traceroute Client Application (Consumer) Operation .  13
   Appendix B.  Open Questions . . . . . . . . . . . . . . . . . . .  14
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   In TCP/IP, routing and forwarding are based on IP addresses.  To
   determine the route to an IP address and to measure the transit
   delays, the traceroute utility is used.  In ICN, routing and
   forwarding are based on name prefixes.  To this end, the problem of
   determining the characteristics (i.e., transit forwarders and delays)
   of, at least, one of the available routes to a name prefix is
   fundamendal.

   This document proposes protocol mechanisms for a traceroute
   equivalent in ICN networks.  This document contains two appendix
   sections: 1) A non-normative appendix section suggesting useful
   properties for an ICN traceroute client application that originates
   traceroute requests and processes traceroute replies and 2) An
   appendix section summarizing the open questions of the current
   protocol design.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].







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2.  Background on IP-Based Traceroute Operation

   In IP-based networks, traceroute is based on the expiration of the
   Time To Live (TTL) IP header field.  Specifically, a traceroute
   client sends consecutive packets (depending on the implementation and
   the user-specified behavior such packets can be either UDP datagrams,
   ICMP Echo Request or TCP SYN packets) with a TTL value increased by
   1, essentially, performing a expanding ring search.  In this way, the
   first IP packet sent will expire at the first router along the path,
   the second IP packet at the second router along the path, etc, until
   the router with the specified destination IP address is reached.
   Each router along the path towards the destination will respond by
   sending back an ICMP Time Exceeded packet.

   The IP-based traceroute utility operates on IP addresses, and in
   particular depends on the IP packets having source IP addresses that
   are used as the destination address for replies.  Given that ICN
   forwards based on names rather than destination IP addresses, that
   the names do not refer to unique endpoints (multi-destination), and
   that the packets do not contain source addresses, a different
   approach is clearly needed.

3.  Traceroute Functionality Challenges and Opportunities in ICN

   In NDN and CCN protocols, the communication paradigm is based
   exclusively on named objects.  An Interest is forwarded across the
   network based on its name.  Eventually, it retrieves a content object
   either from a producer application or some forwarder's Content Store
   (CS).

   An ICN network differs from an IP network in at least 4 important
   ways:

   o  IP identifies interfaces to an IP network with a fixed-length
      number, and delivers IP packets to one or more interfaces.  ICN
      identifies units of data in the network with a variable length
      name consisting of a list of components.

   o  An IP-based network depends on the IP packets having source IP
      addresses that are used as the destination address for replies.
      On the other hand, ICN Interests do not have source addresses and
      they are forwarded based on names, which do not refer to a unique
      end-point.  Data packets follow the reverse path of the Interests
      based on hop-by-hop state created during Interest forwarding.

   o  An IP network supports multi-path, single destination, stateless
      packet forwarding and delivery via unicast, a limited form of
      multi-destination selected delivery with anycast, and group-based



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      multi-destination delivery via multicast.  In contrast, ICN
      supports multi-path and multi-destination stateful Interest
      forwarding and multi-destination data delivery to units of named
      data.  This single forwarding semantic subsumes the functions of
      unicast, anycast, and multicast.  As a result, consecutive (or
      retransmitted) ICN Interest messages may be forwarded through an
      ICN network along different paths, and may be forwarded to
      different data sources (e.g., end-node applications, in-network
      storage) holding a copy of the requested unit of data.  The
      property of discovering multiple available (or potentially all)
      paths towards a name prefix may be desirable for an ICN traceroute
      protocol, since it can be beneficial for congestion control
      purposes.  Knowing the number of available paths for a name can
      also be useful in cases that Interest forwarding based on
      application semantics/preferences is desirable.

   o  In the case of multiple Interests with the same name arriving at a
      forwarder, a number of Interests may be aggregated in a common
      Pending Interest Table (PIT) entry.  Depending on the lifetime of
      a PIT entry, the round-trip time an Interest-Data exchange might
      significantly vary (e.g., it might be shorter than the full round-
      trip time to reach the original content producer).  To this end,
      the round-trip time experienced by consumers might also vary.

   These differences introduce new challenges, new opportunities and new
   requirements in the design of ICN traceroute.  Following this
   communication model, a traceroute client should be able to express
   traceroute requests with some name prefix and receive responses.

   Our goals are the following:

   o  Trace one or more paths towards an ICN forwarder (for
      troubleshooting purposes).

   o  Trace one or more paths along which an application can be reached
      in the sense that Interest packets can be forwarded towards it.

   o  Test whether a specific named object is cached in some on-path CS,
      and, if so, trace the path towards it and return the corresponding
      forwarder.

   o  Perform transit delay network measurements.

   To this end, a traceroute target name can represent:

   o  An administrative name that has been assigned to a forwarder.
      Assigning a name to a forwarder requires a management application




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      running locally, which handles Operations, Administration and
      Management (OAM) operations.

   o  A name that includes an application's namespace as a prefix.

   o  A named object that might reside in some in-network storage.

   In order to provide stable and reliable diagnostics, it is desirable
   that the packet encoding of a traceroute request enables the
   forwarders to distinguish this request from a normal Interest, while
   also allowing for forwarding behavior to be as similar as possible to
   that of an Interest packet.  In the same way, the encoding of a
   traceroute reply should allow for processing similar to that of a
   data packet by the forwarders.

   The term "traceroute session" is used for an iterative process during
   which an endpoint client application generates a number of traceroute
   requests to successively traverse more distant hops in the path until
   it receives a final traceroute reply from a forwarder.  It may be
   desirable that ICN traceroute is able to discover a number of paths
   towards the expressed prefix within the same session or subsequent
   sessions.  To discover all the hops in a path, we need a mechanism
   (Interest Steering) to steer requests along different paths.

   It is also important, in the case of traceroute requests for the same
   prefix from different sources, to have a mechanism to avoid
   aggregating those requests in the PIT.  To this end, we need some
   encoding in the traceroute requests to make each request for a common
   prefix unique, and hence avoid PIT aggregation and further enabling
   the exact matching of a response with a particular traceroute packet.

   The packet types and format are presented in Section 4.  The
   procedures, e.g. the procedures for determining and indicating that a
   destination has been reached, are specified in Section 5.

4.  ICN Traceroute Packet Formats

   Based on the goals mentioned in the previous section, we propose two
   types of traceroute packets, a traceroute request and a reply packet
   type.  Both these packets follow the CCNx packet format
   [CCNMessages], where messages exist within outermost containments
   (packets).









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4.1.  ICN Traceroute Request Packet Format

   The format of the traceroute request packet is presented below:

    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |               |               |                               |
    |    Version    |   TrRequest   |         PacketLength          |
    |               |               |                               |
    +---------------+---------------+---------------+---------------+
    |               |               |               |               |
    |    HopLimit   |    Reserved   |     Flags     |  HeaderLength |
    |               |               |               |               |
    +---------------+---------------+---------------+---------------+
    /                                                               /
    /                       PathSteering TLV                        /
    /                                                               /
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |               Traceroute Request Message TLVs                 |
    |                                                               |
    +---------------+---------------+---------------+---------------+


                     Traceroute Request Packet Format

   The existing packet header fields have similar functionality to the
   header fields of a CCNx Interest packet.  The value of the packet
   type field is TrRequest.  The exact numeric value of this field type
   is to be determined.

   Compared to the typical format of a CCNx packet header [CCNMessages],
   there is a new optional fixed header TLV added to the packet header:

   o  A Path Steering hop-by-hop header TLV, which is constructed hop-
      by-hop in the traceroute reply and included in the traceroute
      request to steer consecutive requests expressed by a client
      towards a common or different forwarding paths.  An example of
      such a scheme is presented in [LIPSIN].











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    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |      PathSteering_Type        |      PathSteering_Length      |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                      PathSteering_Value                       |
    |                                                               |
    +---------------+---------------+---------------+---------------+


                             Path Steering TLV

   The message of a traceroute request is presented below:

    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |        MessageType = 1        |          MessageLength        |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                          Name TLV                             |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                     Traceroute Request Message Format

   The traceroute request message is of type Interest in order to
   leverage the Interest forwarding behavior provided by the network.
   The Name TLV has the structure described in [CCNMessages].  The name
   consists of the target (destination) prefix appended with a nonce
   typed name component as its last component (to avoid Interest
   aggregation and allow exact matching of requests with responses) The
   value of this TLV will be a 64-bit nonce.











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    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |        Name_Nonce_Type        |      Name_Nonce_Length = 8    |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                                                               |
    |                                                               |
    |                       Name_Nonce_Value                        |
    |                                                               |
    |                                                               |
    +---------------+---------------+---------------+---------------+




                      Name Nonce Typed Component TLV

4.2.  Traceroute Reply Packet Format

   The format of a traceroute reply packet is presented below:

    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |               |               |                               |
    |    Version    |    TrReply    |          PacketLength         |
    |               |               |                               |
    +---------------+---------------+---------------+---------------+
    |                               |               |               |
    |            Reserved           |     Flags     | HeaderLength  |
    |                               |               |               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                        PathSteering TLV                       |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                 Traceroute Reply Message TLVs                 |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                      Traceroute Reply Packet Format




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   The header of a traceroute reply consists of the header fields of a
   CCNx Content Object and a hop-by-hop path steering TLV.  The value of
   the packet type field is TrReply.  The exact numeric value of this
   field type is to be determined.

   A traceroute reply message is of type Content Object, contains a Name
   TLV (name of the corresponding traceroute request), a PayloadType TLV
   and an ExpiryTime TLV with a value of 0 to indicate that replies must
   not be cached by the network.

    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |        MessageType = 2        |          MessageLength        |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                            Name TLV                           |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                         PayloadType TLV                       |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                         ExpiryTime TLV                        |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                      Traceroute Reply Message Format

   The PayloadType TLV is presented below.  It is of type
   T_PAYLOADTYPE_DATA, and the data schema consists of 2 TLVs: 1) the
   name of the sender of this reply (with the same structure as a CCNx
   Name TLV), 2) the sender's signature of their own name (with the same
   structure as a CCNx ValidationPayload TLV), 3) a TLV with return
   codes to indicate whether the request was satisfied due to the
   existence of a local application, a CS hit or a match with a
   forwarder's name, or the HopLimit value of the corresponding request
   reached 0.








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    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |       T_PAYLOADTYPE_DATA      |             Length            |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                      Sender's Name TLV                        |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                    Sender's Signature TLV                     |
    |                                                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                       TrReply Code TLV                        |
    |                                                               |
    +---------------+---------------+---------------+---------------+



                      Traceroute Reply Message Format

   The goal of including the name of the sender in the reply is to
   enable the user to reach this entity directly to ask for further
   management/administrative information using generic Interest-Data
   exchanges after a successful verification of the sender's name.

   The structure of the TrReply Code TLV is presented below (16-bit
   value).  The potential values are the following:

   o  1: Indicates that the target name matched the administrative name
      of a forwarder (as served by its internal management application).

   o  2: Indicates that the target name matched a prefix served by an
      application (other than the internal management application of a
      forwarder).

   o  3: Indicates that the target name matched the name of an object in
      a forwarder's CS.

   o  4: Indicates that the the Hop limit reached the 0 value.








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    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +---------------+---------------+---------------+---------------+
    |                               |                               |
    |       TrReply_Code_Type       |    TrReply_Code_Length = 2    |
    |                               |                               |
    +---------------+---------------+---------------+---------------+
    |                                                               |
    |                     TrReply_Code_Value                        |
    +---------------+---------------+---------------+---------------+




                             TrReply Code TLV

5.  Forwarder Handling

   When a forwarder receives a traceroute request, the hop limit value
   will be checked and decremented and the target name (i.e, the name of
   the traceroute request without the last nonce name component) will be
   extracted.

   If the HopLimit value is not expired (has not reached 0), the
   forwarder will forward the request upstream based on CS lookup, PIT
   creation, LPM lookup and the path steering value, if present.  If no
   valid next-hop is found, an InterestReturn is sent downstream.

   If the HopLimit value is equal to zero, the forwarder will generate a
   traceroute reply.  This reply will include the forwarder's own name
   and signature, and a PathSteering TLV.  This TLV initially has a null
   value since the traceroute reply originator does not forward the
   request and, thus, does not make a path choice.  The reply will also
   include the appropriate TrReply Code TLV.

   A traceroute reply will be the final reply of a traceroute session if
   one of the following conditions are met:

   o  Assuming that a forwarder has been given one or more
      administrative names, the target name matches one of them.

   o  The target name exactly matches the name of a content-object
      residing in the forwarder's CS (unless the traceroute client
      application has chosen not to receive replies due to CS hits as
      specified in Appendix A).

   o  The target name matches (in a Longest Prefix Match manner) a FIB
      entry with an outgoing face referring to a local application.



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   The TrReply Code TLV value of the reply will indicate the specific
   condition that was met.  If none of those conditions was met, the
   TrReply Code will be 4 to indicate that the hop limit value reached
   0.

   A received traceroute reply will be matched to an existing PIT entry
   as usual.  On the reverse path, the path steering TLV of a reply will
   be updated by each forwarder to encode its choice of next-hop(s).
   When included in subsequent requests, this path steering TLV will
   allow the forwarders to steer the requests along the same path.

6.  Security Considerations

   Reflection attack concerns can arise when a compromised forwarder
   generates a traceroute reply.  In such cases, the compromised
   forwarder can attach the name of a victim forwarder to the reply
   payload to redirect future administrative traffic towards the victim.
   To mitigate these attack scenarios, the forwarder that generates a
   reply has to sign the name TLV contained in the reply message.  When
   the client receives a traceroute reply, it will be able to verify
   that the key that signed the name in the reply message can be trusted
   for both the traceroute prefix and the name of the forwarder that
   generated the reply.  Instead of including a raw name TLV and a
   signature in the reply message, the forwarder can include its
   routable prefix(es) encoded as a signed NDN Link Object [SNAMP].
   Each forwarder can generate the signature of its own name or its LINK
   Object in the beginning of its operation instead of doing so during
   the generation of each individual reply.

   This approach does not protect against on-path attacks, where a
   compromised forwarder that receives a traceroute reply replaces the
   forwarder's name and the signature in the message with its own name
   and signature to make the client believe that the reply was generated
   by the compromised forwarder.  To mitigate such attack scenarios, a
   forwarder can sign the reply message itself.  In such cases, the
   forwarder does not have to sign its own name in reply message, since
   the message signature protects the message as a whole and will be
   invalidated in the case of an on-path attack.

   Signing each traceroute reply message can be expensive and can
   potentially lead to computation attacks against forwarders.  To
   mitigate such attack scenarios, the processing of traceroute requests
   and the generation of the replies can be handled by a separate
   management application running locally on each forwarder.  Serving
   traceroute replies is a load on the forwarder.  The approaches used
   by ICN applications to manage load may also apply to the forwarder's
   management application.




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   We should also note that traceroute requests have the same privacy
   characteristics as regular Interests.

7.  References

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

7.2.  Informative References

   [CCNMessages]
              Mosko, M., Solis, I., and C. Wood, "CCNx Messages in TLV
              Format.", 2016, <https://tools.ietf.org/html/draft-irtf-
              icnrg-ccnxmessages-03>.

   [LIPSIN]   Jokela, P. and et al, "LIPSIN: line speed publish/
              subscribe inter-networking, ACM SIGCOMM Computer
              Communication Review 39.4: 195-206", 2009.

   [SNAMP]    Afanasyev, A. and et al, "SNAMP: Secure namespace mapping
              to scale NDN forwarding, IEEE Conference on Computer
              Communications Workshops (INFOCOM WKSHPS)", 2015.

Appendix A.  Traceroute Client Application (Consumer) Operation

   This section is an informative appendix regarding the proposed
   traceroute client operation.

   The client application is responsible for generating traceroute
   requests for prefixes provided by users.

   The overall process can be iterative: The first traceroute request of
   each session will have a HopLimit of value 1 to reach the first hop
   forwarder, the second of value 2 to reach the second hop forwarder
   and so on and so forth.

   When generating a series of requests for a specific name, the first
   one will typically not include a PathSteering TLV, since no TLV value
   is known.  After a traceroute reply containing a PathSteering TLV is
   received, each subsequent request might include the received path
   steering value in the PathSteering header TLV to drive the requests
   towards a common path as part of checking the network performance.
   To discover more paths, a client can omit the PathSteering TLV in
   future requests.  Moreover, for each new traceroute request, the



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   client has to generate a new nonce and record the time that the
   request was expressed.  It will also set the lifetime of a request,
   which will have semantics similar to the lifetime of an Interest.

   Moreover, the client application might like not to receive replies
   due to CS hits.  A mechanism to achieve that would be to use a
   Content Object Hash Restriction TLV with a value of 0 in the payload
   of a traceroute request message.

   When it receives a traceroute reply, the client would typically match
   the reply to a sent request and compute the round-trip time of the
   request.  It should parse the PathSteering value and decode the
   reply's payload to parse the the sender's name and signature.  The
   client should verify that both the received message and the
   forwarder's name have been signed by the key of the forwarder, whose
   name is included in the payload of the reply (by fetching this
   forwarder's public key and verifying the contained signature).  In
   the case that the client receives an TrReply Code TLV with a valid
   value, it can stop sending requests with increasing HopLimit values
   and potentially start a new traceroute session.

   In the case that a traceroute reply is not received for a request
   within a certain time interval (lifetime of the request), the client
   should time-out and send a new request with a new nonce value up to a
   maximum number of requests to be sent specified by the user.

Appendix B.  Open Questions

   In this section, we describe the open questions of our ICN traceroute
   protocol design.

   The current design can steer subsequent traceroute requests along the
   same forwarding path (single-path traceroute).  It can also
   opportunistically forward subsequent requests along different paths
   if the client does not attach a PathSteering TLV to the requests
   letting the network decide how to forward them.  However, one of the
   objectives of ICN traceroute, as stated in Section 3, is to discover
   a specific number of available paths and steer requests along them in
   a deterministic manner (multi-path traceroute).  The open question is
   how the ICN multi-path traceroute client could keep track of the
   multiple available paths and iteratively traverse them by using
   distinct PathSteering TLVs.

   In the previous appendix section, we mentioned that in order to avoid
   receiving replies due to CS hits (bypass the caches along the path),
   a client can use a Content Object Hash Restriction TLV with a value
   of 0 in the payload of a traceroute request message.  If, in the
   future, a specific Interest cache control mechanism to bypass caches



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   is added to the CCNx protocol specification, this mechanism can be
   used by the traceroute clients as well.

Authors' Addresses

   Spyridon Mastorakis
   UCLA
   Los Angeles, CA
   US

   Email: mastorakis@cs.ucla.edu


   Jim Gibson
   Cisco Systems
   Cambridge, MA
   US

   Email: gibson@cisco.com


   Ilya Moiseenko
   Cisco Systems
   Cambridge, MA
   US

   Email: iliamo@mailbox.org


   Ralph Droms
   Cisco Systems
   Cambridge, MA
   US

   Email: rdroms.ietf@gmail.com


   Dave Oran
   Cisco Systems
   Cambridge, MA
   US

   Email: daveoran@orandom.net








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